Method for producing detectable warnings on surfaces and products thereof

ABSTRACT

A method for producing detectable warnings ( 16 ) on surfaces ( 14 ) includes providing a mat ( 30 ) with a top surface ( 38 ) and a bottom surface ( 36 ). The mat ( 30 ) has a pattern of truncated dome-shaped cavities ( 34 ) with a dome upper surface ( 28 ) and a dome lower surface. The mat ( 30 ) has at least one aperture ( 40 ), wherein the aperture ( 40 ) passes from the dome upper surface ( 28 ) to the top surface ( 38 ) of the mat ( 30 ). The method further includes securing the bottom surface ( 36 ) of the mat ( 30 ) to a substrate surface ( 14 ). The method also includes preparing a viscous substance ( 32 ) having the ability to cure into a solid, injecting the viscous substance ( 32 ) into each aperture ( 40 ) of the mat ( 30 ) to fill the truncated dome-shaped cavity ( 34 ), permitting the viscous substance ( 32 ) to substantially cure, and removing the mat ( 32 ) to expose raised detectable warnings ( 16 ) on the substrate surface ( 14 ).

FIELD OF THE INVENTION

The present invention relates to the field of surface treatment, andmore specifically to the creation of detectable warnings that protrudefrom a target surface.

BACKGROUND OF THE INVENTION

With increasing public awareness regarding persons with disabilities,many local and regional laws, regulations, and ordinances have beenpassed that require modifications to existing structures andconsideration of the disabled when undertaking new construction. Perhapsthe most significant new legislation has been the enactment of theAmericans with Disabilities Act (ADA). This Act sets forth numerousrequirements regarding access to and use of facilities by the disabled.

One of the more widely recognized disabilities is impaired vision. Whilepreviously the incorporation of tactile indicia and detectable warningswas discretionary, under the ADA, suitable tactile indicia anddetectable warnings must be provided in many situations. Moreover, thetypes of acceptable detectable warnings are now regulated.

Specifically, the ADA now requires detectable warnings on the walkingsurface of curb ramps or on a walking surface prior to the surface orramp crossing or adjoining a vehicular way not otherwise separated bycurbs, railings, or other such elements. Similarly, if there are nocurbs, railings, or the like between a walking surface and perhaps, forexample, a reflecting pool, detectable warnings must be used.

Detectable warnings have been defined as “a standardized integralsurface feature built in or applied to walking surfaces or otherelements to warn individuals with visual impairments of hazards on acirculation path.” The technical specifications of the ADA require thatdetectable warnings on walking surfaces have a specific truncated domepattern. This unique pattern is intended to provide a consistent anduniform surface that is distinctive from other materials and, therefore,recognizable as a warning to pedestrians that they are approaching apotentially dangerous area. The detectable warnings must contrastvisually with adjoining surfaces, and material used to provide contrastmust be an integral part of the walking surface. Though not required, a70% contrast ratio is recommended.

When discussing detectable warnings for pedestrians, three traditionaltechniques of achieving such warnings have been used: surface forming,etching, and deposition. In surface forming, a desired pattern iscreated in the surface during its formation stage. For example, when aconcrete walk is being formed, the detectable warning pattern is createdtherein usually by stamping the surface or by applying a prefabricatedsurface treatment. Etching, if done during the formation of the surface,provides a low cost method for treating a traveled surface to have therequired detectable warning. However, if etching is desired on anexisting surface, a material removal process must usually be used whichoften incorporates the use of abrasives or the like. With both of thesemeans, however, there is little ability to incorporate visual contrastor other required or desirable aspects identified in the ADA.

Deposition techniques are usually carried out after the surfaceformation process has been completed. Thus, such techniques are suitablefor both new and old work. A significant problem associated with manyother deposition techniques is that the resulting detectable warningsmay be abrupt so as to engender the tripping of a person using thatsurface. In addition, many surfaces having detectable warnings areslippery and/or lack contrast when compared to the base surface.Moreover, it is desirable to have detectable warnings that are uniformin appearance—a quality that some deposition techniques fail to provide.

SUMMARY OF THE INVENTION

One embodiment of a method for producing detectable warnings on surfacesincludes providing a mat with a top surface and a bottom surface. Themat has a pattern of truncated dome-shaped cavities with a dome uppersurface and a dome lower surface. The mat also has at least oneaperture, wherein the aperture passes from the dome upper surface to thetop surface of the mat. The method further includes securing the bottomsurface of the mat to a substrate surface. The method also includespreparing a viscous substance having the ability to cure into a solid,injecting the viscous substance into each aperture of the mat to fillthe truncated dome-shaped cavity, permitting the viscous substance tosubstantially cure, and removing the mat to expose raised detectablewarnings on the substrate surface.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects and many of the attendant advantages of thisinvention will become more readily appreciated as the same become betterunderstood by reference to the following detailed description, whentaken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a perspective view of detectable warnings formed on a target,substrate surface.

FIG. 2 is a cross-sectional view of a detectable warning formed on atarget surface as shown in FIG. 1.

FIG. 3 is a bottom perspective view of a mat used to form the detectablewarnings, wherein dome-shaped sections have been formed on the bottomsurface of the mat.

FIG. 4 is a top perspective view of the mat depicted in FIG. 3.

FIG. 5 is a cross-section of the mat depicted in FIGS. 3 and 4, whereinthe mat has been secured to a target surface such that a blendedmaterial may be injected into the dome-shaped cavities in the mat toform the detectable warnings depicted in FIG. 1.

FIG. 6 is a cross-sectional view of the mat depicted in FIGS. 3 and 4being removed from the target surface to reveal the detectable warningsdepicted in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, a substrate or target surface 14 having a patternof detectable warnings in the form of truncated domes 16 formed thereonis shown. The truncated domes are illustrated as arranged in an“in-line” or “square” pattern as shown in FIG. 1. The rows of truncateddomes may instead be rotated (for example at 45 degrees) in relation tothe substrate surface 14 to produce an offset pattern. Preferably, thetruncated domes are spaced at least 1.6″ from the center of onetruncated dome to the center of the adjacent truncated dome, and no morethan 2.4″ apart for both the in-line pattern and the offset pattern. Inaddition, a multiple sinusoidal pattern in a stacked relationship, asshown in U.S. Pat. No. 5,385,770, may instead be used to provide agreater likelihood that an object, in constant contact with surface 14,will encounter a truncated dome 16 in the least distance. For ease ofillustration and clarity, only the in-line pattern is shown.

A cross section of a truncated dome 16 bonded to substrate 14 is shownin FIG. 2. Inclined peripheral surfaces 20 may have curved upper andlower transitions 22 and 24 with upper surface 26 and substrate 14,respectively, so that an object such as a cane, shoe, or foot, as wellas an implement such as a shovel or squeegee, will not jam or lodge inthe otherwise sharp corners or edges created at these interfaces.Beneficially, these curved transitions 22 and 24 increase the truncateddome's resistance to dislodgment from lateral impacts by permitting acertain degree of impact redirection. The truncated domes 16 arepreferably at least 0.9″ in diameter along the bottom of the truncateddome 16, and no more than 1.4″ in diameter. Along the top of thetruncated dome, the diameter is preferably at least 0.45″ and no morethan 0.6″. The truncated domes 16 are preferably approximately 0.2″ inheight. However, other truncated dome shapes and sizes may also be used.For instance, as shown in U.S. Pat. No. 5,385,770, additional designsmay include an elongated elliptical design, a diamond shaped design, anasymmetrical elongated elliptical design, or a dumbbell design.Regardless of the form of truncated dome 16, each truncated dome ischaracterized as having an inclined peripheral surface and somewhatrounded or curved transitions between both the lower substrate 14 andthe upper surface of the truncated dome 16.

Referring to FIG. 3, a mat 30 or similar element may be used to createthe afore-described detectable warnings or truncated domes 16 on asubstrate surface 14. The mat 30 may consist of either a rigid,flexible, or semi-flexible material, where the mat 30 may be preferablyformed using a molding technique, such as injection molding. The matmold may also be designed to produce dome-shaped cavities 34 in the mat30 during the molding process. The mold may include an upper and lowerportion, and each portion of the mat mold may contain a portion of amold cavity. The mold may also include inwardly extending projectionsthat generally conform to the shape of a truncated dome 16 to form thedome-shaped cavities 34 during the molding process.

During the molding process, the upper and lower portions of the mat moldare coupled together to define the mold cavity therebetween. At leastone inlet channel may be included in the mold to allow the inflow ofmaterial through the inlet channel and into the mold cavity. Aninjection nozzle may inject material through the inlet channel and intothe mold cavity. The injected material may fill the mold cavity to formthe mat 30. After the material injected into the mold cavity has cured,the mold portions may be separated and the mat 30, with dome-shapedcavities 34, may be removed from the mold.

Each dome-shaped cavity 34 formed during the molding process representsa mold for forming the desired truncated domes 16 on the substratesurface 14. Thus, the material of the mat 30 defining each dome-shapedcavity 34 is in roughly complimentary relationship to the desiredphysical dimensions of the truncated dome 16. The dome-shaped cavities34 may be formed during the molding process on the bottom surface of themat 36, such that the bottom of the dome-shaped cavities 34 align thebottom surface of the mat 36. The dome-shaped cavities 34 may bearranged in a desired pattern to enhance the detectability of the targetsurface.

Referring to FIGS. 3 and 4, an aperture 40 may be formed in the top ofeach dome-shaped cavity 34, where the aperture 40 passes from the uppersurface 28 of the dome-shaped cavity 34 to the upper surface of the mat38. The apertures 40 may be formed during the molding process at thesame time the dome-shaped cavities 34 are formed. The mat mold mayinclude inwardly extending cylindrical projections that extend from thetop of the dome-shaped projections. These inwardly extending cylindricalprojections will form an aperture that passes from the upper surface 28of the dome-shaped cavity 34 to the upper surface of the mat 38 when themold cavity is injected with material.

Referring to FIG. 5, the truncated domes 16 may be formed by firstplacing the mat 30 on a substrate surface 14. The mat 30 may include asealant or adhesive surface 42 that covers the bottom surface of the mat30. Thus, the mat 30 may be placed on the substrate surface 14 such thatthe bottom surface of the mat 30 may adhere to the substrate surface 14by means of the adhesive surface 42. After the mat 30 is placed upon thesubstrate surface 14, a material 32 may be injected into each aperture40 to fill the dome-shaped cavities 34. The material 32 may be used tofill the dome-shaped cavities 34 by using a manually operated squirtbottle or other manually operated or powered device with a nozzlesufficiently small to inject the material 32 into the aperture 40. Afterthe material 32 has completely, or at least substantially, cured instasis, the mat 30 may be removed to reveal the truncated domes 16, asshown in FIG. 6. Once the mat 30 has been removed, a final coat ofviscous catalyzed material may be applied to the substrate surface 14and the truncated domes 16 to smoothen any abnormalities or blemishesand help ensure an even appearance.

The truncated domes 16 of the present invention may be formed frommaterial 32, which may comprise a methacrylate monomer blended withbinders, pigments, and an abrasive. Ideally, the blended material hasgood abrasion resistance, chemical resistance, and longevity. In oneform of the present invention, the composition of the detectablewarnings may be a methacrylate monomer blend having glass fiber binders,pigments, and reflective material. The use of a methacrylate monomerhelps engender strong bond characteristics with normally encounteredsubstrate surfaces such as asphalt, concrete, and wood. The use of glassfibers enhances structural properties of the detectable warnings andreduces the amount of resin mixture needed for any given application.The percentage pigment chosen provides adequate color contrast under theprovisions of the ADA. The use of reflective material such as glassspheres or beads enhances low light detection of the detectable warningsand further decreases the amount of monomer needed. Finally, thepercentage abrasive not only increases the potential coefficient offriction of the warnings, but also provides additional strength as anaggregate and decreases the overall amount of resin needed for a givenapplication.

While a preferred embodiment of the invention has been illustrated anddescribed, it will be appreciated that various changes can be madetherein without departing from the spirit and scope of the invention.

1. A method for producing detectable warnings on surfaces, comprising:(a) providing a mat with a top surface and a bottom surface, the mathaving a pattern of truncated dome-shaped cavities, said truncateddome-shaped cavities having a dome upper surface and a dome lowersurface, said mat having at least one aperture, wherein the aperturepasses from the dome upper surface to the top surface of the mat; (b)securing the bottom surface of the mat to a substrate surface; (c)preparing a viscous substance having the ability to cure into a solid;(d) injecting the viscous substance into the apertures of the mat tofill the truncated dome-shaped cavities; (e) at least substantiallycuring the viscous substance; and (f) removing the mat to expose raiseddetectable warnings on the substrate surface.
 2. The method of claim 1,wherein the truncated dome-shaped cavities are circular in shape.
 3. Themethod of claim 2, wherein the detectable warnings have a dome lowersurface with a diameter of at least 0.9″ and no more than 1.4″, a domeupper surface with a diameter of at least 0.45″ and no more than 0.6″,and a height of at least 0.2″ and no more than 0.3″.
 4. The method ofclaim 1, wherein the truncated dome-shaped cavities are selected fromshapes consisting of diamond shapes and dumbbell shapes.
 5. The productresulting from the method of claim
 1. 6. The method of claim 1, whereinthe truncated dome-shaped cavities are arranged in a sinusoidal row,each row being in stacked relationship to another similar row.
 7. Themethod of claim 1, wherein the viscous substance is a monomer.
 8. Theproduct resulting from the method of claim
 7. 9. The method of claim 1,further comprising providing an adhesive layer on the bottom surface ofthe mat, such that the bottom surface of the mat may adhere to thesubstrate surface.
 10. The method of claim 1, wherein the step ofpreparing the viscous substance further comprises the step of combiningat least one adjunct to create a viscous blend.
 11. The method of claim10, wherein the at least one adjunct comprises glass fibers, glassspheres, glass filaments, pigments, or abrasives.
 12. The method ofclaim 1, wherein the viscous substance is selected from the groupconsisting of polyester, polyethylene, polyurethane, polypropylene,polymethacrylate, polystyrene, polystyrene-acrylonitrile,polyvinylchloride, vinyl chloride acetate, nylon, rayon, acetate,acetate butyrate, rubber, methylmethacrolate, and polycarbonate.
 13. Themethod of claim 12, wherein the step of preparing the viscous substancefurther comprises the step of combining at least one adjunct to create aviscous blend.
 14. The method of claim 13, wherein the at least oneadjunct comprises at least one of: glass fibers, glass spheres, glassfilaments, pigments, or abrasives.
 15. The method of claim 1, furthercomprising applying a final layer of viscous catalyzed material to thesubstrate surface and raised detectable warnings.
 16. A method forproducing detectable warnings on substrate surfaces, using a mat with atop surface and a bottom surface, with a plurality of cavities formed inthe mat from the bottom surface of the mat to form a pattern oftruncated dome-shaped cavities having a dome upper surface and having anaperture extending from the dome-shaped cavity to the top surface of themat, the method comprising: (a) securing the bottom surface of the matto a substrate surface; (b) preparing a viscous substance having theability to cure into a solid; (c) infusing the viscous substance intothe apertures of the mats to fill the truncated dome-shaped cavities;(d) permitting the viscous substance to at least substantially cure; and(e) removing the mat to expose raised detectable warnings on thesubstrate surface.
 17. The method of claim 16, wherein the truncateddome-shaped sections are selected from a group consisting of circular,elongated ellipses, diamond-shaped and dumbbell-shaped.
 18. The methodof claim 16, wherein each detectable warning has a diameter of at least0.9″ and no more than 1.4″ along the bottom of the detectable warning, adiameter of at least 0.45″ and no more than 0.6″ along the top of thedetectable warning, and a height of at least 0.2″ and no more than 0.3″.19. The method of claim 16, wherein the viscous substance is a monomer.20. The method of claim 16, wherein the step of preparing the viscoussubstance further comprises the step of combining at least one adjunctto create a viscous blend.
 21. The method of claim 16, furthercomprising applying a final layer of viscous catalyzed material to thesubstrate surface and the raised detectable warnings.
 22. A mat used forproducing detectable warnings on substrate surfaces, the warningscomposed of a curable, initially viscous, substance, the mat comprisinga top surface, a bottom surface, a plurality of cavities formed in themat extending upwardly from the bottom surface in the shape of atruncated dome, and an aperture extending downwardly from the topsurface of the mat to the upper surface of the truncated dome cavity.23. The mat according to claim 22, wherein the bottom surface of the matis adapted to be secured to the substrate surface so that when theviscous substance is introduced into the truncated dome cavities throughthe apertures, the viscous substance does not substantially leak ormigrate from the mat cavity at the interface of the bottom surface ofthe mat cavity and the substrate surface.